Accelerate

The full name of the book is:  Accelerate: The Science of Lean Software and DevOps: Building and Scaling High Performing Technology Organizations.

Copied from the wikipedia entry:

Considering that case studies weren’t sufficient for their research, the authors analysed 23,000 data points from a variety of companies of various different sizes (from start-up to enterprises), for-profit and not-for-profit and both those with legacy systems and those born digital. DevOps research conducted by the authors and summarised in Accelerate demonstrates four key metrics that are indicators of software delivery performance, leading to higher rates of profitability, market share and customer satisfaction for their respective companies. The four metrics identified are as follows:

• Change Lead Time – Time to implement, test, and deliver code for a feature (measured from first commit to deployment)
• Deployment Frequency – Number of deployments in a given duration of time
• Change Failure Rate – Percentage of failed changes over all changes (regardless of success)
• Mean Time to Recovery (MTTR) – Time it takes to restore service after production failure

Teh book is considered teh bible of why DevOps works, I recommend it to get insights and to understand why teh aforementioned metrics are the relevant ones to guide you through the process to implment DevOps.